Final answer:
In the context of equity theory, an employee who perceives unfair treatment and opts to work harder is choosing to change their inputs to restore a sense of equity.
Step-by-step explanation:
Within the framework of the equity theory, if an employee perceives inequitable treatment and decides to work harder, the choice they have made is e. change their inputs. This decision is one of the potential reactions to perceived inequity according to the theory.
The employee could have also chosen to adjust their perceptions, select a different referent, attempt to change their outcomes, or leave the situation, but in this case, they've opted to increase their level of effort as a means of restoring equity to their work situation.